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-rw-r--r--fs/autofs4/root.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index aa4c5ff8a40..0533d37c73a 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -242,6 +242,7 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags)
{
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ struct dentry *new;
int status = 0;
/* Block on any pending expiry here; invalidate the dentry
@@ -318,6 +319,27 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags)
spin_lock(&dentry->d_lock);
dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
spin_unlock(&dentry->d_lock);
+
+ /*
+ * The dentry that is passed in from lookup may not be the one
+ * we end up using, as mkdir can create a new one. If this
+ * happens, and another process tries the lookup at the same time,
+ * it will set the PENDING flag on this new dentry, but add itself
+ * to our waitq. Then, if after the lookup succeeds, the first
+ * process that requested the mount performs another lookup of the
+ * same directory, it will show up as still pending! So, we need
+ * to redo the lookup here and clear pending on that dentry.
+ */
+ if (d_unhashed(dentry)) {
+ new = d_lookup(dentry->d_parent, &dentry->d_name);
+ if (new) {
+ spin_lock(&new->d_lock);
+ new->d_flags &= ~DCACHE_AUTOFS_PENDING;
+ spin_unlock(&new->d_lock);
+ dput(new);
+ }
+ }
+
return status;
}